The present invention relates generally to the field of ethernet networks, and more particularly to determining end host physical connections on ethernet networks.
Ethernet is a computer technology used for communicating over a local area network (LAN). An ethernet frame is a method of organizing data for transfer over the ethernet computer network. Data or commands that are transferred over the network are broken up into small portions of data called data packets. The data packet running on an ethernet link is called an ethernet packet. This ethernet packet is used to transport an ethernet frame as payload.
Layer 2 network topology is the data link layer in a data communications network that provides a link between two (2) directly connected nodes. In the field of network management, discovery of complete and accurate layer 2 network topology is helpful, if not required. In the context of data centers and cloud infrastructures, it is known that it is helpful to discover the physical connectivity: (i) between switches; and/or (ii) between switches and end hosts. Different techniques exist to discover a physical connection between a switch and an end host. One of these techniques is to use LLDP (link layer discovery protocol). This technique works only when both the switch and the end host are LLDP enabled. However, a network administrator may disable LLDP on switches for security reasons. Some switches may not even have support for LLDP protocol. Another technique is to check if a switch port is marked as “edge” in the STP (spanning tree protocol) configuration. STP is usually disabled when the network is configured so that there is no possibility of creating loops. Yet another technique is to analyze the FDB (forwarding database) tables of the switches. Switches “learn” the MAC (media access control) addresses of possible destinations by observing the source MAC addresses of packets arriving into the switch through its different ports.